Processing of titanium net shapes by SLS/HIP

Abstract

SLS/HIP is a hybrid direct laser fabrication method that combines the strengths of selective laser sintering (SLS) and hot isostatic pressing (HIP). SLS can produce complex shaped metal components with an integral, gas impermeable skin. These components can then be directly post-processed to full density by containerless HIP. SLS/HIP is envisioned as a rapid, low-cost replacement for conventional metal can HIP processing. The advantages of freeform fabrication combined with in situ HIP encapsulation include the ability to perform containerless HIP, no adverse container–powder interactions, reduced pre-processing time, and fewer post-processing steps compared to conventional HIP of canned parts. SLS/HIP is currently being developed for Inconel® 625 superalloy and Ti-6Al-4V. This paper focuses on microstructure and mechanical properties of SLS processed and HIP post-processed Ti-6Al-4V. SLS/HIP technology for Ti-6Al-4V was demonstrated by fabricating a subscale AIM-9 missile guidance section housing to specification. This work is funded jointly by DARPA and ONR under contract N00014-95-C-0139 titled `Low Cost Metal Processing Using SLS/HIP'.